#include <stdio.h>
#include <stdint.h>
#include <string.h>

void test01() {
    char buffer[10] = {0x00};
    memcpy(buffer, "hello", 6);
    printf("%s, len=%llu\n", buffer, strlen(buffer));
    buffer[3] = 0x00;
    printf("%s, len=%llu\n", buffer, strlen(buffer));
}
int main(int argc, char *argv[]) {
    test01();
    return 0;
}